(A/N: For Jen! Sorry this isn't all out smut like you wanted, but this is what came out! I promise smut with my next gift for you!)
It was bound to happen. Two men, both deceptively old despite their outward appearance. Both jaded by life's so called 'pleasures' , finding solace in material hobbies, rather than emotions. Many holy books say that taking such joy in material is a sin as you cannot take it with you into the promised paradise. Yet, the two were certain they would live forever, eternal works of art existing until time itself ended. They had no need for paradise.
It was bound to happen. Their respective partners, one certain to die within a few years, the other granted immortality through his faith. Both could not see the reasoning behind their partners' beliefs. One dedicated to life's evanescent 'art'. True beauty, fleeting, lasting for only a few seconds before burning away to nothing. The other following what was most likely another blind faith, killing and torturing to appease his blood thirsty God. The two found solidarity in their equal failure to understand their partners and comrades.
It was bound to happen. Their aforementioned partners were away, doing those strange things that made them happy. The two left to their own devices, one sat gutting a fresh body. His hollow shell of a body not feeling the warmth of the blood, his blank eyes not seeing the mirrored emptiness in the corpse's starless eyes. While normally this held most of his time, transforming worthless humans into beautiful, eternal puppets. Today, Akasuna no Sasori's only pleasure, turned into bland, tedious work. Leaving his workbench, he discarded his tools and went out into the main part of this cavern like home, searching for something to pass his endless time.
It was bound to happen. Kakuzu, long tired by the all too familiar clicking of calculator buttons as he calculated Akatsuki's earnings. Not seeing deaths, bloodshed, battles, only numbers and figures. For the first time in his long life, he was tired of counting the bag of notes that was always too small for his liking. So, leaving the calculator and the now half empty bag of money, he too left his room to try and find something to occupy his old mind.
It was bound to happen. They were bound to bump into each other, and find solidarity in their lack of motivation. They were bound to go back to Kakuzu's room, telling themselves it was only to collect the mask the old man had left there.
It was bound to happen. The two of them, feeling more than either had done in a very long time, tangled together, moving in perfect timing, like the clockwork their lives had become. The mediocrity of their existence thrown to the wind as they gave in to the carnal desires neither had known they still harbored.
It was bound to happen. That in this so called sinful act in their sinful lives, the two would find paradise.